The present invention relates to a an optical or optoelectronic array of the type used, for example, in optical modules which are used as the source for signals transmitted over optical fibers. By means of modules of this type, light emitted from a semiconductor laser is fed into optical fibers, which is needed, for example, for applications in the areas of telecommunications, pumping lasers, printing and photographic equipment, material processing, medical technology, illumination and display technology, metrology or analytics.
Optical modules of this type are disclosed, for example, in publications U.S. Pat. Nos. 4,818,053 and 4,997,279. Each of them shows an optical bench on which a semiconductor laser, an optical fiber and a focusing lens in a bracket is positioned to transmit the radiation emitted from the semiconductor laser into the optical fiber, where the fiber is held in a fiber sleeve. Both the lens and the optical fiber are aligned longitudinally along the optical axis of the beam emitted by the laser.
The adjustment of the two components is carried out in such a way that first of all the focusing lens is adjusted in three degrees of freedom of translation along the optical axis of the beam emitted by the laser. After the lens has been fixed in position, the optical fiber in turn is adjusted in three degrees of freedom of translation along the optical axis and fixed in position. The disadvantage here is that the adjustment of the two components is performed sequentially in two separate steps. This requires a high degree of sophistication in the equipment as well as the expenditure of a great deal of time.
The object of the present invention is to make available optical or optoelectronic arrays as well as uses for arrays of this type, with which optical or optoelectronic modules can be constructed and adjusted simply and which ensure precise beam characteristics during their entire life and even under adverse conditions.
This-object is achieved under the optical or optoelectronic array in accordance with claim 1 and also under the use in accordance with claim 27. Advantageous further developments of the array according to the invention or the uses according to the invention are given in the specific dependent claims.
The optical or optoelectronic arrays according to the invention show an assembly holder with an assembly base. The assembly holder can be positioned with the assembly base on an assembly surface of an optical bench. Furthermore, the assembly holder has a full-length open seat for an optical or optoelectronic module. It is vital that the assembly base is constructed in such a way that it is moveable on the assembly surface of the optical bench in a first plane of adjustment parallel to the assembly surface, while the optical or optoelectronic module and the seat of the assembly holder are formed in such a way that the optical or optoelectronic module is moveable only in a second plane of adjustment, not parallel to the first plane of adjustment, ideally perpendicular.
The optical or optoelectronic module can consist of an element holder with optical and/or optoelectronic components located on it.
One configuration of the assembly holder, for example, is a U-section open at the top, between the flanges of which the element holder is located. The distance between the two flanges is dimensioned such that only a small gap remains on both sides of the element holder between the element holder and the flanges. One use of this embodiment under the invention of the optical or optoelectronic array provides for positioning at least one focusing lens and an optical fiber on the element holder in appropriately shaped seats. This array can be set up without any adjustment. The path of the common optical axis of the assembled optical or optoelectronic module is determined by the alignment of the optical axes of the focusing lens, the optical fiber and any other optical and/or optoelectronic components to each other and is therefore dependent on the manufacturing tolerances of the element holder. By adjusting the optical module in up to three degrees of freedom of translation and up to three degrees of freedom of rotation in a single step, the optical axes of the module and of the beam emitted by the laser diode can aligned to each other, and the optimal distance of the laser diode to the optical module can be set. By means of this embodiment of the optical or optoelectronic array according to the invention, it is possible to position all the optical and/or optoelectronic components located on the element holder jointly in the beam path of the light emitted by the laser diode and thus to achieve a simple and correct adjustment of the optical or optoelectronic module.
Advantageously the element holder and the assembly holder are formed in such a way that the element holder is moveable relative to the optical bench in all degrees of freedom.
During the process of adjustment and locking in position, the element holder is held, for example, by a gripping device which is mounted on a positioning system. By means of this positioning system, which can be moved advantageously in 6 axes, the element holder and thus the optical module are adjusted for position. Because of its particular configuration, the assembly holder is moved as well in the first plane of adjustment during the positioning procedure for the element holder, that is to say a subsequent adjustment of the assembly holder is not necessary.
After adjustment has been completed, the element holder can be locked in position in the assembly holder with adhesive, and the assembly holder can be held in position on the optical bench. In this process the element holder is held in position only laterally against the flanges of the assembly holder, and the assembly holder is only held in place by its underside on the assembly surface of the optical bench. The open space between the element holder and the upper side of the base plate of the assembly holder is advantageously not filled with adhesive.
Because of the special configuration of the assembly holder and of the element holder, the gaps between the first element holder and the first assembly holder are extremely narrow, and so only a small gap has to be bridged with adhesive. The result is that material shrinkage of the adhesive during curing is negligible. As a consequence, the adjustment of the element holder in the assembly holder remains unchanged even after the adhesive has cured.
Some examples of optoelectronic arrays under the invention are given in the ensuing descriptions. Similarly, examples of uses of the arrays under the invention, i.e. optical or optoelectronic modules, are to be given.